Heliornithidae
Encyclopedia
The Heliornithidae are a small family
of tropical bird
s with webbed lobes on their feet like those of grebe
s and coot
s. The family overall are known as finfoots, although one species
is known as a Sungrebe
. The family is composed of three species in three genera
.
, but do not call frequently. Their legs and feet are brightly coloured and, unlike grebes, they are capable of walking well and even moving quickly on land.
s, and forest. Finfoots are territorial, probably for much of the year and certainly when breeding. They are not thought to undertake regular migrations
, but some birds do regularly disperse and they are quick to colonise new areas of suitable habitat.
s of various sorts being the most frequently observed component of their diet. Little quantitative information on finfoot diet exists, but they have also been recorded eating molluscs, crustacean
s, spiders, frog
s, fish
and some leaves and seeds. Unlike grebes they do not dive to obtain food, instead picking prey off the water's surface or foraging on the shore.
, the exact timing of which is dependent on the local climate. The breeding behaviour of the Masked Finfoot is almost entirely unknown. All three species exhibit some changes in appearance prior to breeding - Masked Finfoots develop a fleshy knob above the bill, and the plumage
of the male African Finfoot and female Sungrebe also change. There is considerable variation within the finfoots on several aspects of breeding; in the Sungrebe the nest building and incubation
duties are shared between the sexes, in the African Finfoot the female alone incubates. The nests of all finfoots are untidy bowls of sticks, twigs, and reeds suspended in vegetation above water.
is found in tropical Africa
on streams in woodland. The Masked Finfoot
has a scattered distribution from Eastern India down through southeast Asia
to the Wallace Line
. The Sungrebe
is found in tropical Central and South America. Finfoots are highly secretive and many aspects of their biology are unknown to science.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of tropical bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s with webbed lobes on their feet like those of grebe
Grebe
A grebe is a member of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter...
s and coot
Coot
Coots are medium-sized water birds that are members of the rail family Rallidae. They constitute the genus Fulica. Coots have predominantly black plumage, and, unlike many of the rails, they are usually easy to see, often swimming in open water...
s. The family overall are known as finfoots, although one species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
is known as a Sungrebe
Sungrebe
The Sungrebe or American Finfoot is a bird which breeds in tropical Central and South America from southern Mexico to northeast Argentina and southern Brazil....
. The family is composed of three species in three genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
.
Description
Finfoots resemble rails; they have long necks, slender bodies, broad tails, and sharp, pointed bills. They have a diverse range of callsBird song
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs are distinguished by function from calls.-Definition:The distinction between songs and calls is based upon...
, but do not call frequently. Their legs and feet are brightly coloured and, unlike grebes, they are capable of walking well and even moving quickly on land.
Habitat
Finfoots are found in numerous habitats in the tropics as long as there is water and cover. It is uncertain why cover is so essential to finfoots, but they are extremely secretive and often overlooked. Their ranges extend from coastal creeks to fast-moving mountain streams, most commonly being found in large slow moving bodies of water. They also use swamps, reed beds, mangroveMangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s, and forest. Finfoots are territorial, probably for much of the year and certainly when breeding. They are not thought to undertake regular migrations
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, but some birds do regularly disperse and they are quick to colonise new areas of suitable habitat.
Diet and feeding
Finfoots feed on a wide range of foods, insectInsect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s of various sorts being the most frequently observed component of their diet. Little quantitative information on finfoot diet exists, but they have also been recorded eating molluscs, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, spiders, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and some leaves and seeds. Unlike grebes they do not dive to obtain food, instead picking prey off the water's surface or foraging on the shore.
Breeding
All three species tend to breed after the wet seasonWet season
The the wet season, or rainy season, is the time of year, covering one or more months, when most of the average annual rainfall in a region occurs. The term green season is also sometimes used as a euphemism by tourist authorities. Areas with wet seasons are dispersed across portions of the...
, the exact timing of which is dependent on the local climate. The breeding behaviour of the Masked Finfoot is almost entirely unknown. All three species exhibit some changes in appearance prior to breeding - Masked Finfoots develop a fleshy knob above the bill, and the plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
of the male African Finfoot and female Sungrebe also change. There is considerable variation within the finfoots on several aspects of breeding; in the Sungrebe the nest building and incubation
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
duties are shared between the sexes, in the African Finfoot the female alone incubates. The nests of all finfoots are untidy bowls of sticks, twigs, and reeds suspended in vegetation above water.
Species
There are three species. The African FinfootAfrican Finfoot
The African Finfoot is an aquatic bird inhabiting the rivers and lakes of western, central, and southern Africa.-Description:...
is found in tropical Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
on streams in woodland. The Masked Finfoot
Masked Finfoot
The Masked Finfoot, , is an aquatic bird from the fresh and brackish wetlands of southeastern Asia, Indochina, Malaysia and Indonesia...
has a scattered distribution from Eastern India down through southeast Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
to the Wallace Line
Wallace Line
The Wallace Line separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present...
. The Sungrebe
Sungrebe
The Sungrebe or American Finfoot is a bird which breeds in tropical Central and South America from southern Mexico to northeast Argentina and southern Brazil....
is found in tropical Central and South America. Finfoots are highly secretive and many aspects of their biology are unknown to science.
External links
- Heliornithidae videos on the Internet Bird Collection